subroutine write_file_info(lunit,i_str,o_str,c_str)
  implicit none
  integer,intent(in) :: lunit
  character :: i_str*(*),o_str*(*),c_str*(*)

900 format("Names of io files")
901 format(1x,"Input file =",1x,a)
902 format(1x,"Output file =",1x,a)
903 format(1x,"Check file =",1x,a)

  write(lunit,*)
  write(lunit,900)
  write(lunit,901) trim(i_str)
  write(lunit,902) trim(o_str)
#ifdef DEBUG
  write(lunit,903) trim(c_str)
#endif

  return

end subroutine write_file_info
